syzbot


BUG: soft lockup in fq_pie_timer (2)

Status: upstream: reported C repro on 2023/08/29 01:49
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+34ded2ce3dea42412908@syzkaller.appspotmail.com
First crash: 291d, last: 57d
Bug presence (1)
Date Name Commit Repro Result
2023/12/23 upstream (ToT) 5254c0cbc92d C [report] BUG: soft lockup in fq_pie_timer
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in fq_pie_timer (2) net C done 6 4d08h 171d 0/27 upstream: reported C repro on 2023/12/27 13:54
upstream BUG: soft lockup in fq_pie_timer (4) net syz 5 277d 327d 23/27 fixed on 2023/10/12 12:48
upstream INFO: rcu detected stall in fq_pie_timer net C error 35 870d 1088d 20/27 fixed on 2022/03/08 16:11
linux-5.15 INFO: rcu detected stall in fq_pie_timer origin:lts-only C done 23 299d 389d 0/3 upstream: reported C repro on 2023/05/22 23:26
linux-6.1 BUG: soft lockup in fq_pie_timer C done 7 371d 379d 3/3 fixed on 2023/07/22 07:09
upstream BUG: soft lockup in fq_pie_timer (2) net C error done 3 416d 483d 0/27 closed as invalid on 2023/05/26 05:46
upstream BUG: soft lockup in fq_pie_timer net C error error 10 612d 649d 0/27 closed as invalid on 2022/11/18 11:06
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2023/09/09 00:29 2h32m fix candidate upstream job log (0)

Sample crash report:
watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [ksoftirqd/1:21]
Modules linked in:
irq event stamp: 1155813
hardirqs last  enabled at (1155812): [<ffff80001223c77c>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline]
hardirqs last  enabled at (1155812): [<ffff80001223c77c>] _raw_spin_unlock_irq+0x3c/0x90 kernel/locking/spinlock.c:202
hardirqs last disabled at (1155813): [<ffff800012158784>] __el1_irq arch/arm64/kernel/entry-common.c:468 [inline]
hardirqs last disabled at (1155813): [<ffff800012158784>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:486
softirqs last  enabled at (593028): [<ffff800008020d7c>] softirq_handle_end kernel/softirq.c:414 [inline]
softirqs last  enabled at (593028): [<ffff800008020d7c>] __do_softirq+0xc1c/0xe38 kernel/softirq.c:600
softirqs last disabled at (593035): [<ffff8000081ca554>] run_ksoftirqd+0x68/0x258 kernel/softirq.c:934
CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted 6.1.87-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
pstate: 00401005 (nzcv daif +PAN -UAO -TCO -DIT +SSBS BTYPE=--)
pc : pie_calculate_probability+0x360/0x7bc
lr : pie_calculate_probability+0x360/0x7bc net/sched/sch_pie.c:360
sp : ffff800019f078d0
x29: ffff800019f07900 x28: 00051eb851eb851e x27: fffffff0a3da8872
x26: 0000000000000000 x25: ffff0000e603b8b0 x24: 1fffe0001cc07716
x23: 1fffe0001a90fb60 x22: ffff0000d487db00 x21: 0000000000000000
x20: 1fffe0001cc07716 x19: 0000000000000000 x18: 0000000000000140
x17: 0000000000040012 x16: ffff8000084fb32c x15: 0000000000000000
x14: 1ffff00002b0a0b0 x13: dfff800000000000 x12: ffff7000033e0f14
x11: 0000000000ff0100 x10: 0000000000000000 x9 : ffff0000c0a59bc0
x8 : ffff800010706a00 x7 : ffff80001070eacc x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff80000831e454
x2 : 0000000000000000 x1 : fffffff0a3da8872 x0 : 00051eb851eb851e
Call trace:
 pie_calculate_probability+0x360/0x7bc net/sched/sch_pie.c:360
 fq_pie_timer+0x22c/0x540 net/sched/sch_fq_pie.c:391
 call_timer_fn+0x1c0/0xa1c kernel/time/timer.c:1504
 expire_timers kernel/time/timer.c:1549 [inline]
 __run_timers+0x554/0x718 kernel/time/timer.c:1820
 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1833
 __do_softirq+0x314/0xe38 kernel/softirq.c:571
 run_ksoftirqd+0x68/0x258 kernel/softirq.c:934
 smpboot_thread_fn+0x4b0/0x96c kernel/smpboot.c:164
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/19 16:49 linux-6.1.y 6741e066ec76 af24b050 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: soft lockup in fq_pie_timer
2023/12/23 10:16 linux-6.1.y 4aa6747d9352 fb427a07 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: soft lockup in fq_pie_timer
2023/08/29 06:20 linux-6.1.y 024f76bca9d0 7ba13a15 .config console log report syz [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: soft lockup in fq_pie_timer
2023/12/23 07:04 linux-6.1.y 4aa6747d9352 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: soft lockup in fq_pie_timer
2023/08/29 01:47 linux-6.1.y 024f76bca9d0 7ba13a15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: soft lockup in fq_pie_timer
* Struck through repros no longer work on HEAD.